MMC Benefits Handbook
Effect on Other Benefits
Making before-tax and/or after-tax contributions has no effect on your Social Security benefits because your before-tax and after-tax contributions are subject to Social Security taxes.
Making before-tax and/or after-tax contributions to the Plan will have no effect on your other Company benefits that are salary-related. Your contributions to the Stock Purchase Plan will continue to be calculated on the basis of your eligible base pay, as defined under the Stock Purchase Plan (see "Eligible Base Pay" under "Glossary" in the Stock Purchase Plan section), before deductions.